First live births after non-fixation cryopreserved ovarian tissue transplantation in Japan

This study aimed to report the first successful live births following ovarian tissue transplantation (OTT) in patients with cancer treatment-induced premature ovarian insufficiency (POI) in Japan and evaluate a novel non-fixation technique, the Circular String Arrangement.

Two patients who developed POI following treatment for Ewing sarcoma underwent OTT using our novel non-fixation technique. The Circular String Arrangement technique involves placing ovarian tissue fragments in a bead-like formation within peritoneal pockets. Both patients underwent assisted reproductive technology treatment following restoration of ovarian function. Histological examination was performed to assess minimal residual disease in the transplanted tissue.

Both patients experienced successful restoration of ovarian function post transplantation. Following multiple oocyte retrievals, both women achieved pregnancy through vitrified-warmed embryo transfer, resulting in healthy live births at term. The Case 1 patient delivered vaginally at 40 weeks (birth weight 3462 g), whereas the Case 2 patient underwent cesarean section at 38 weeks due to pre-eclampsia (birth weight 2930 g). Laparoscopic examination confirmed successful tissue engraftment with visible follicular development.

This study presents the first live births following OTT in cancer survivors with chemotherapy-induced POI in Japan. The Circular String Arrangement technique showed feasibility for OTT, with successful engraftment and ovarian function restoration in both cases.